A web of fabric or other flexible material can carry code marks in the form of code fields. The methods hitherto in use for "reading" the fields encompass the use of a reading device comprised of a reader head and an evaluating logic or system. The signal flow produced at the reader head when code fields pass underneath it in such methods is passed to and converted by the evaluating logic into the pertaining identification mark or marking in conformity with the pertaining code field.
Methods of this type are particularly known in textile manufacturing and upgrading industries. Such methods allow automated processing and process control, as well as optimization of operations, through the use of electronics and data processing, such that the completion of job orders can be done more efficiently while making optimal use of the available means of production.
Identification marks on the material web enable the automatic recognition, sensing, or scanning of moving web sections or portions, and the completion-control as a function of the identified markings or codes. Also, the continuous monitoring of the entire production sequence, treatment sequence, or flow is made possible in this manner.
In general terms, the sensing or recognition of the identification marks is carried out in such a way that the reader head substantially continuously scans the moving material over that width of the material which assuredly contains the code fields. The code fields may be formed, for example, by sections of a piece of cloth and/or plastic/synthetic foil or laminate, with a coding in the form of a scanning pattern made up of perforations, lines, or the like.
The signal flow produced as a result of the scanning or sensing operation is processed in the evaluating logic and is converted into the identification marking contained in the pertaining code field that is being scanned, and the identification marking is subsequently further processed through a computer, data processor, or the like.
The signal flow is continuous even in the absence of passage of code fields at the reader head, due to irregularities, defects, disruptions and the like in the surface of the web passing at the reader head, or due to holes, tears and the like in the web in general. Thus, the evaluating logic is required to continuously examine the signal flow and to determine whether or not the information at hand contains an actual identification, i.e., the logic is required to carry out a full signal processing even in the absence of code fields on the material which is being scanned during passage beneath the reader head. This requires a high data retention and processing capacity in the evaluating logic which may become overloaded with stray data at any time in such a way that the commencement of transmission and adequate recognition of useful data is obstructed. Saturation of the logic capacity by spurious marks which are not part of a code field are a major problem.